30-60-90

if z= 8√2 then
x= 4√2
y= 8√6 can u tell me if this is rite or wrong? Because I think I got it write but is marked wrong. Same goes for this:

if z=6√2 then
x= 3√2
y= 6√6

DISTANCE

1. in order to return her friend's bike, a girl rides it to her friend's house at a speed of 9mph. She then walks back home at a speed of 3mph. If the total time of the round trip was 1.5 hours, how far was her friend's house?

my equation: 9(1.5-x)+3x=1.5 every number I could think of wouldn't work when I plug it in.

2. if a plane flies from mount pleasant to waltersville in 5 hours with a headwind of 25mph and returns in 4 hours w/ a tailwind of 20mph, find the airspeed of the plane.

5(x-25)=4(x-20) am I right to subtract it? And both tailwinds are different, how am I supposed to calculate it?

3. a boat's speed on its speedometer read 18 mph going downstream, and it reaches its destination in 1.25 hours. The return trip takes 1.75 hours at 18 mph on the speedometer. Find the speed of the current.

this I completely have no idea what to do. Can u give me a formula to solve for it?

4. a plane flies in a headwind of 22 mph from east grove to uniontown in 6 hours and returns in 4 hours with a tailwind of 22 mph. find the distance between the airports.

I will understand this question if I know what tailwind and headwind means give me a formula or explain how it is supposed to be done.^_^

Assuming that x and z are the two non-hypotenues sides:
if z= 8√2 then
x= 4√2

This is obviously wrong, as tan^-1 of 0.5 is 26, not 30. So I'm assuming that your y values are wrong also.

Your first question can be solved easily. You need to get out of the mindset of using trial and error. Use algebra. Expand the brackets and simplify.

For #1, the distance to her friends house is the same both ways, but the round trip took 3/2 hours.

d=rt, t=d/r.



Solve for d.

http://img53.imageshack.us/img53/5302/306090ne9.png
That's how the triangle looked like (mine is a bit off I think but that's the concept)

And for my other questions is headwind or tailwind add or subtract or both the same?

Quote:

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Originally Posted by nike23

http://img53.imageshack.us/img53/5302/306090ne9.png
thats how the triangle looked like (mine is a bit off i think but thats the concept)

and for my other questions is headwind or tailwind add or subtract or both the same?

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If the hypoteneuse, z, is , then and

Code:

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      z                      *
                      *    *
              *            *  y
          *                  *
    *                        *
*                            *
***************************
                x

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